+1 except - you can get the same field of view and relative mirror location with the far smaller, trimmer and less likely to snag on things Third Eye Hard Shell Helmet Mirror but to get to get a mount that is nearly as bulletproof and the Safe Zone you have to make your own. I do every time i buy a new, different helmet. I cut out sheet aluminum and bend the top to fit the inside of the helmet visor nicely. Have it come down say 3/4" then I bend the bottom out in an "L". Try the mirror on for location and adjust as needed. Fiberglass both sides with thin fiberglass cloth and epoxy resin. (Do one side, trim to the metal with a sharp trim knife when 3/4" hard, flip and do same on the other side. Sand if necessary to get the nice fit again. Drill matching #2 screw size holes in visor and mount. Find some small screws that look good (Ace Hardware has many choices). Install and screw on mirror. A lot of work, yes, but this mount will outlast as many helmets of that model as you can find, puts the mirror in the perfect place, does very well on rough roads, looks good (I paint them black with model paint). And when you do snag and break one, the next mirror is like $17, That mount isn't breaking. Edit: and other plus is that the mirror clamp unscrews as intended so taking it off to clean the helmet or store or transport is easy.

I started this 15 years ago and I've made three. (Three models of helmet.) Why helmet manufacturers and the mirror people cannot talk to each other and come up with a system like mine (that requires a standard and two tiny holes) is completely beyond me.

Ben